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rule of thumb: how long do you leave a tube preamp on versus turning it off then back on?

I just upgraded to an Audio Research REF 10 with 12 tubes and I am wondering how to best preserve the tubes. How long sitting turned on is equal to the wear and tear of turning it off then on again? I had a Rogue RP 7 with just four tubes so I didn't worry about this issue so much, I just turned it on when I began to listen then off at the end of the evening. Now I'm wondering where the sweet spot is? Away for a hour, two, three, turn it off when? Am I over-thinking this issue?
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yogiboy's avatar
yogiboy
5,450 posts
 
+1 @ millercarbon

HOW DO I KNOW WHEN MY TUBES NEED REPLACING?

Power tubes like EL34’s and KT88’s are good for about 2500 hours or more. But may go longer in an amplifier with a conservative design. Small signal tubes with numbers like 12AX7, 12AU7, and 6922, and rectifier tubes like 5AR4 may go 10,000 hours. So you get years and years of enjoyment. Using a tube tester may or may not tell you if you need a replacement. The best approach is to buy a new set of tubes, and install them. If they don’t sound a lot better, put in the old ones and suck every bit of life out of them.




petg60
1,486 posts
 
Use and enjoy what you paid for, you knew that tubes wear out.
Just power them off at end of each session. It is not wise to leave them on and be away for some time. Normally a tube will last longer in hours if not switched on and off but a year has approx 9000hrs so you will need replacements at least twice a year if left on all the time. Otherwise with normal use replacement would take place every 2-3 years.

G

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jjss49
6,601 posts
 
Best not to leave powered up tube gear unattended


important advice, to be heeded, by @noromance -- better safe than sorry - even for preamps, i have seen tube rectifiers go up in smoke
elliottbnewcombjr
5,081 posts
 
after burn in (Brent Jesse advised 60 hours on, no signal needed)

then: on, 20 minutes, magic, off. preamp and amp 
ebm
9,311 posts
 
Nobody leaves tube on turn on 1/2 hour before listing.HELLO!!
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